1. Field of the Invention
The invention relates to a solenoid valve device that includes a solenoid that is supplied with driving current to generate magnetic flux and a valve element that is moved by the magnetic flux generated from the solenoid, a hydraulic apparatus equipped with the solenoid valve device, and a hydraulic power steering system equipped with the hydraulic apparatus.
2. Discussion of Background
For example, Japanese Patent Application Publication No. 2009-079644 (JP 2009-079644 A) describes a conventional solenoid valve. An example of how a solenoid valve is used is as follows: the solenoid valve is used to provide communication between a first hydraulic chamber and a second hydraulic chamber within a hydraulic cylinder of a hydraulic power steering system.
In order to further accurately control the solenoid valve, it is necessary to detect the position of a valve element. For example, a mechanical position sensor may be used to detect the position of the valve element. In this case, however, the position sensor may contact the valve element, resulting in interfere with movement of the valve element.